Map-ds

Java code for map  ds

Author: Thashini

Examination_map.java

@@ -0,0 +1,61 @@
+import java.util.*;  
+import java.io.*;     
+
+class Examination_map {
+
+    public static void main(String [] args) throws Exception {
+      
+        /* Read input and save as entries in  HashMap */                  
+
+        Scanner in = new Scanner(System.in);
+                System.out.print("Enter no of candidates: ");
+                int n = in.nextInt();   // Get the number of entries
+
+        HashMap<Integer, String> map = new HashMap<>();    // Create the hashMap
+       
+        System.out.println("\n Input Entries to the List \n");
+
+            for (int i = n-1; i >= 0;  i -= 1) {   // Loop to compare no of candidates and 1, then decreases no of candidates by 1
+               
+                               
+                                                               
+                Scanner logp = new Scanner(System.in);          // Get index numbers as variable name'id' to add to hashMap
+                    System.out.println("Index Number: ");      
+                    int id = logp.nextInt(); 
+                    
+                    Scanner logn = new Scanner(System.in);         // Get names as variable name'name' to add to hashMap
+                    System.out.println("Name: ");    
+                    String name = logn.next();
+                
+                map.put(id, name);   // put each name and id to the map (key-id, value-name) 
+            }
+   
+        System.out.println("\n\tCandidate List\n");
+        System.out.println("\tIndex No.    |    Name");
+        System.out.println("--------------------------------");
+
+       
+        for (Map.Entry<Integer, String> entry : map.entrySet())                       // Iterating over the hashMap's entry set using for loop
+                System.out.println("\t"+entry.getKey() + "\t|\t" + entry.getValue()); // print each key-value pairs
+
+                System.out.println("\n--------------------------------\n");
+
+                System.out.println("\nEnter the index number to get the name");
+                Scanner nw = new Scanner(System.in);    // Get a key element to find the relevent value
+                Integer d;
+                   // parameter to assign above key element (id2)
+        
+        
+        /* Read each query and check if its in the HashMap */
+        while((d = nw.nextInt()) != null) {    
+          
+            if (map.containsKey(d)) {        // Check whether the particular key value 's' is being mapped into the hashMap
+                System.out.println("\n"+d+" Index No 's name: "+(map.get(d)));     // Get the relevent value 
+            } 
+            else {
+                System.out.println("Not found");
+            }
+        }
+       
+    }
+}